The past perfective is often enough used according to the time relationship "before a time in the past"; however, the more complete principle, perhaps not often stated, is somewhat different. In fact it is also used for denoting time after a given time in the past. This is explained in A comprehensive grammar of the English language; nevertheless, this grammar also shows, that, as felt, the use of the tenses should be the opposite; past and past perfective are equivalent in the subordinate, but apparently not in the main clause.
(CoGEL § 4.24)
The past perfective usually has the meaning of 'past-in-the-past', and can be
regarded as an anterior version either of the present perfective or of the
simple past. Consider the following examples:
♦ No wonder Miss Matthews' French was excellent - she had lived
in Paris since childhood. [1]
♦ When we bought it, the house had been empty for several years. [2]
These can be diagrammed as in Fig 4.24a, which is a special case of the
general perfective diagram Fig 4.18 :
More technically, the past perfective may be said to denote any event or state
anterior to a time of orientation in the past. The three meanings of 'state',
'event' or 'habit' can all occur. Whereas [1] and [2] have
illustrated the 'state' meaning, [3] and [4] illustrate 'event' and 'habit'
respectively:
♦ The goalkeeper had injured his leg, and couldn't play. [3]
♦ It was foolish to fire McCabe: in two seasons, he had scored more
goals than any other player. [4]
When transposed into the 'past in the past' by means of the past perfective,
the contrast between the simple past and the present perfective is neutralized :
♦ My aunt had lived in Italy for four years. [5]
♦ He had died in 1920, before his son was born. [6]
In [5], the four-year period could either be a period leading up to T2, or a
period which had ceased before T2, as would be clear in:
♦ In her youth, my aunt had lived in Italy for four years. That's why she
spoke Italian so well.
Thus [5] could be a projection further into the past of either [7] or [8]:
♦ My aunt lived in Italy for four years. [7]
♦ My aunt has lived in Italy for four years. [8]
But of course, the past perfective does not have to refer to a more remote
time than that referred to by the simple past. In some cases, particularly in a
clause introduced by after, the two constructions can be more or less
interchangeable:
After places the eating (T2) after Sandra's return (which we may call T3), so
the past perfective, which places T3 before T2, is redundant. What difference
it does make is a matter of the 'standpoint' of the speaker. In [9] the 'past in
past' time T3 is identified as being earlier than T2 by the past perfective; but
in [10] it is left to the conjunction after to signal this temporal relation.
Note fig 4.18
